Closing a door

An out-of-town patient who had a patent foramen ovale (PFO), the case I closed 4 years ago, called me as I was writing this article to tell me she was in need of a second ablation procedure, now a left-sided one for a remaining atrial focus. Her options were now affected by the device I had placed for her well-documented recurrent cerebral events at the time. Still I sighed. If one can judge by the number of devices that have been developed and improved for PFO closure, their relative ease of deployment, the infrequent complications, and the increasing market potential (migraine sufferers, divers), of those with documented cryptogenic embolism, closure devices are here to stay [1–3]. The devices are increasingly slick in design, they are easy to deploy, and are safe in follow-up, as is the case of the modified device in this report. With the ease of placement, comes also peace of mind, perhaps simply because neither our patients nor we want to have a first, let alone a second stroke! That being said, whether they are truly as vital or effective in preventing many presumed recurrent paradoxical embolic events still awaits definitive proof from the randomized control studies underway. Only a rare patient referred for closure prefers long-term anticoagulation to a low risk, frequently outpatient procedure, substantiated by sound clinical evidence supporting efficacy. Spies et al. now report their long-term experience with the Intrasept occluder in 247 patients with presumed embolism who were followed for up to about 4.5 years, although some were only followed for 6 months or so [4]. The Intrasept occluder is a modification of a previous Cardia Inc. occluder, now with an articulating center that improves alignment of the umbrellas across the atrial septum. The residual shunt rate was 10% at 1 year, detected by contrast echocardiography and unlikely to increase over time. Six patients (2.4%) had definite recurrent embolic events, significant in that the median follow-up period was only 14 months. From this report, one can conclude that the Intrasept occluder is easily deployed, and both relatively safe and effective when deployed in a high volume center by very experienced operators who do use alternative devices, as well. The age range was 21–77 with a median age of 53 years. On first glance, this seemed high to me but a quick review of my personal database of atrial closures revealed a similar median age. Indeed many older patients do not have carotid disease, atrial fibrillation, or an atheromatous aorta. A PFO is something we can close, perhaps reducing the risk of recurrence. However, I always tell those older patients to continue a platelet inhibitor indefinitely, just in case. Is the Intrasept PFO occluder better or equal in safety and efficacy to the other devices currently available or under study? On the basis of limited registry data and reports available with differing populations studied to date, we simply do not know. We may never know, given the paucity of prospective trials done in this field to date. This brings me to a subject we do not like to discuss: complications. Some of the reported late complications range from erosion of a device into the aorta, allergic reactions to the nickel in the nitinol used in select devices, and arrhythmias. Although a recurrent embolic event is not necessarily a complication, it has been, and thrombus formation on the device is not only possible but may be dependent on the device chosen [5]. In this report, the complications were indeed few, but did include supraventricular tachycardia requiring long-term medical therapy in one patient, a case of endocarditis, requiring surgical removal of the device, and of interest, elective removal of the device in two patients at the time of coronary bypass surgery. Does retrieval at surgery speak of a lack of confidence in the device or was there evidence of incomplete endothelialization necessitating their removal? Recurrent thromboembolism, unless related to documented thrombus on the device, would not be considered a complication, but rather a failure of the device or a failure in detecting an underlying issue, perhaps a hypercoagulable state. Missing the opportunity to detect this disease could